The present invention relates generally to methods of fluorination and, more particularly, to the use of O.sub.2 F.sub.2 for the extraction of actinides from sintered and other oxides, and from waste nuclear materials containing the actinides by producing therefrom the hexafluorides of the actinides present or soluble actinide compounds thereof. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).
Fluorinating agents useful for recovering actinides as volatile hexafluorides from refractory oxides, scrap material and from incinerator ash, are known. However, the difficulty with all of the known materials which are capable of performing these tasks is that little reaction takes place at or below room temperature. The requisite high temperatures and harsh oxidizing environments result in the deterioration of any containment vessels and transfer equipment as well as in the destruction of the intended end products, the actinide hexafluorides themselves. Moreover, the reaction of a fluorinating agent with every warm surface in its pathway makes it very difficult to introduce the fluorinating agent into the region of interest.
Dioxygen difluoride was first prepared and isolated in 1933. A careful investigation of the properties of this material was performed by A. G. Streng in his article entitled "The Oxygen Fluorides" published in Chem. Rev. 63, 607 (1963), the disclosure therein hereby being incorporated by reference herein. Of particular interest in this article is the mention by the auther of the explosive reaction of O.sub.2 F.sub.2 when placed in contact with a sheet of platinum covered with platinum fluoride at 160.degree. K. Even at this low temperature, it would appear that O.sub.2 F.sub.2 is unstable in the presence of metallic surfaces. The use of this material then for recovering actinides from refractory oxide actinide containing compounds or from incinerator ash which are located inside metal vessels would appear to be impossible especially if the O.sub.2 F.sub.2 had to be first introduced into the region of interest through metallic plumbing.
The inventors wish to point out that the use of O.sub.2 F.sub.2 for the fluorination of actinide fluorides and oxyfluorides thereof is the subject matter for copending patent application Ser. No. 636,656. "Method For Fluorination Of Actinide Fluorides And Oxyfluorides Thereof Using O.sub.2 F.sub.2," filed on Aug. 1, 1984 by Phillip G. Eller et al.